The Data Management and Analysis (DMA) Core (Core C) will provide a source of data management and data analysis expertise in the proposed multi-component program project. Primarily, the DMA Core supports Projects Mil, which are aimed at understanding the precursors and early manifestations of ASDs in infants and toddlers. In addition, the expertise of the DMA personnel will be applied to the work proposed in Projects IV and V. The broad objectives of the DMA Core are to (1) support the efforts of the Assessment Core (AC) in the collection of Center-shared data for Projects I-V; (2) support the efforts of Projects I-V, especially Projects Mil, in the collection of project-specific data; (3) further develop, in collaboration with AC, tools and procedures for ensuring and monitoring the accuracy and confidentiality of all collected data; (4) provide expert advice on issues related to study design, sample construction, and power considerations; (5) facilitate communication and the sharing of data among investigators by capitalizing on the computer networking and computing facilities available through the DMA and associated facilities; (6) provide statistical support, analytical expertise, and software support to investigators in the evaluation of project-specific hypotheses; and (7) investigate novel and exploratory statistical approaches, including joint analyses across Projects Mil and data mining. The DMA will benefit from a pool of extraordinary expertise under the leadership of Dr. Grigorenko (whose areas of active research cross the disciplines of population and molecular genetics, psychology, methodology, and learning and developmental disabilities) and Dr. Chang (Chairman of the Statistics Department at Yale). They are longtime collaborators in joint projects and publications, and have been involved in all of the preparation meetings for the Yale ACE. They also participated in individual project area design and data analytic strategies. On the basis of these reviews, Drs. Grigorenko and Chang recruited personnel with specific expertise likely to benefit individual projects, both within Yale (Drs. Cicchetti, Emerson and Leeb) and nationally (Drs. Linda Collins, Jack McArdle, and Bengt Muthen).